A total eclipse occurs somewhere in the world about once every 18 months on average, and that has been the case for all of human history. For millennia, humans have been documenting their views as the moon moved between Earth and the sun, blocking out the sun鈥檚 light and revealing its swirling outer layers.

The earliest confirmed written record of a solar eclipse comes from the 13th century BC, when scribes in China wrote that the sun had been 鈥渆aten鈥�. Scientific and religious texts continued to document eclipses up until the present day, and researchers now use these texts to study both how eclipses have changed in the intervening centuries and how human views of them have evolved throughout time. This particular petroglyph, carved into stone by the early Pueblo people in New Mexico, is thought to represent a total solar eclipse that occurred on 11 July 1097. The swirls around its perimeter bear a resemblance to the corona of the sun, which is only visible when the moon hides the rest of the solar disc.

More recent art depicts religious and scientific figures observing eclipses directly. This watercolour from the late 17th century shows a group of French missionaries observing a solar eclipse with King Narai of Siam and his court in April 1688. They can be seen using the projection method to avoid looking directly at the sun: the light passes through a telescope and projects the shape of the eclipse on a screen beneath it. This technique is still commonly used today, with pinhole cameras or even just the gaps between shadows cast by leaves on the ground.

Scientific sketches of eclipses proliferated as science became more of a formal, professionalised pursuit. This drawing, by astronomer Jos茅 Joaqu铆n de Ferrer, depicts an eclipse that occurred over New York on 16 June 1806. Watching this event led de Ferrer to give the outermost layer of the sun, the corona, its name. He was among the first people reported to have hypothesised that the corona must be part of the sun, not the moon, because of its incredible size 鈥� it can stretch to as much as 20 times the width of the main disc of the sun, as he sketched here.

The first photograph of a total solar eclipse with enough detail on the corona to be scientifically useful was taken on 28 July 1851 by Julius Berkowski at the Royal Observatory in K枚nigsberg, Prussia. With help from the astronomers at the observatory, he attached a small telescope to a device called a heliometer, a specialised instrument for measuring the sun. This daguerreotype was an 84-second exposure taken through the telescope. Not only is the corona visible, but several eruptions can be seen blasting from the sides of the sun over the edge of the moon.

After Berkowski鈥檚 image, the ability to take photographs of eclipses became more widespread around the world. These images were taken by William and Frederick Langenheim on 26 May 1854 in Philadelphia, Pennsylvania. Without access to the scientific tools Berkowski used to magnify the light from the eclipse, they were forced to use small cameras to create these miniature daguerreotypes, the largest of which is just 7.2 centimetres tall and the smallest less than half that size.

The total solar eclipse that swept over parts of Africa and South America on 29 May 1919 proved to be one of the most important eclipses ever observed. This image comes from the expedition that astronomer Arthur Eddington made to the African island of Principe. He and his team photographed several stars located close to the sun to compare their apparent positions in the sky before and then during the eclipse. In this image, the stars are marked with horizontal lines. The comparison proved that the gravity of the sun bent the light coming from those stars, providing some of the first evidence for Albert Einstein鈥檚 theory of general relativity and creating a new understanding of the workings of the universe.

Eclipses became popular photographic targets for scientists and non-scientific photographers alike. This image, taken by Frederick Goetz on 24 January 1925, shows an effect called the diamond ring, or Baily鈥檚 beads. This effect occurs just at the beginning and end of totality, when the edge of the moon is nearly, but not quite, covering the entire disc of the sun. Ridges and craters on the moon鈥檚 surface let through only a few rays of sunlight, creating the glare that earned Goetz鈥檚 inscription of 鈥淪igns and Wonders鈥�.

Modern images of solar eclipses, such as this one taken in California on 11 July 1991, display the corona in much more detail than has ever been achievable before. Past observations revealed an astonishing mystery: the corona is about 300 times hotter than the sun鈥檚 surface. Eclipses provide prime opportunities to try to figure out how and why it gets so hot, plus research how we might be able to predict solar activity someday to mitigate its potential effects on satellites, astronauts and even electrical grids on Earth.

The sun itself is, of course, not the only thing that researchers study during eclipses. As seen in this image taken in Chile on 2 July 2019, during a total solar eclipse the sky darkens almost completely. Temperatures drop precipitously. Birdsong ceases almost entirely. Through studying how animals react, researchers try to decipher what they may be feeling and thinking, and how they perceive the unexpected darkness.

When viewing an eclipse from the ground, it can be hard to imagine the scale of it. These images of an 8 April 2024 eclipse, taken by NASA鈥檚 Deep Space Climate Observatory (DSCOVR) satellite, show that handily. The dark spot moving across the planet in these pictures is the shadow of the moon. People standing within that spot witness totality, and those along the edges see only partial eclipses.

Our ability to image and understand these phenomena has come a long way since petroglyphs in stone walls 鈥� imagine what we鈥檒l be able to see in another few thousand years.

Western Europe鈥檚 first total solar eclipse since 1999 will happen on 12 August and see eclipse chasers travel to eastern Greenland, western Iceland and northern Spain for totality, when the moon covers the sun鈥檚 disc and the usually hidden solar corona bursts into view. Solar and atmospheric scientists will be among them 鈥� and above them.

It is tempting to think total solar eclipses have been made obsolete for scientists by spacecraft. NASA鈥檚 Parker Solar Probe has flown through the sun鈥檚 corona, while the European Space Agency鈥檚 Solar Orbiter and study the sun from space. can even create artificial eclipses in orbit. So why do scientists still need to chase the moon鈥檚 shadow across Earth?

The answer is simple: total eclipses offer cheap and accessible opportunities to study both the sun and Earth. 鈥淩esearch groups that have novel ideas can go to an eclipse and take observations without having to bid for tens of millions of pounds鈥� worth of grants from NASA or the European Space Agency 鈥� the barrier to entry is much lower,鈥� says , a solar physicist at the Laboratory for Atmospheric and Space Physics in Boulder, Colorado.

One example is the , which will send teams from several US universities to Spain and Iceland to study atmospheric responses to the eclipse. Balloons released in Spain will reach an altitude of 27 to 37 kilometres, carrying 360-degree cameras, ozone instruments and radio experiments. Icelandic teams will launch balloons carrying radiosondes, devices that can monitor pressure, temperature, humidity and other atmospheric parameters. The idea is to measure the effects the eclipse has on the planetary boundary layer, the atmosphere鈥檚 lowest region where its behaviour is most heavily influenced by warm air rising from the ground.

NASA鈥檚 WB-57 high-altitude aircraft can measure polarised coronal light and will fly for the 2026 eclipse. Flying high avoids the problem of cloud cover obscuring the view, while also minimising atmospheric interference. 鈥淎t high altitude, you can observe infrared light that you can鈥檛 observe from the ground,鈥� says French.

During the 2024 total solar eclipse, 鈥� an experiment funded by the US National Science Foundation and NASA 鈥� used telescopes spread along the path of totality to create a 1-hour timelapse of the corona. This will be repeated during the 2026 eclipse, ahead of a plan to produce a timelapse of the corona with the larger experiment聽during the longer eclipse that will happen in August 2027. Totality in 2027 will last much longer because the new moon will be closer to Earth, and the path of totality is close to the equator, where Earth effectively bulges out towards the moon.

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鈥淢ost of the scientific instruments at an eclipse are not just taking photographs, but collecting measurements of spectra,鈥� says French. Spectroscopy can reveal the speed, temperature and density of plasma in the corona. 鈥淲hen you observe specific spectra, this can give you information on the speed of plasma moving in the sun, and can tell you about the temperature and the density of plasma sloshing around the sun,鈥� he says.

Other eclipse scientists ask a fundamental question: what is the radius of the sun? Because the sun has no solid surface, its visible edge is difficult to define. Yet tiny differences can shift the predicted edge of the path of totality. The , a group of researchers scattered across the world, records flash spectra at the path鈥檚 edge to refine eclipse maps and calculate the sun鈥檚 actual radius.

The eclipse may also offer a rare chance to test whether aurora can be detected during totality. NASA scientist , founder of citizen science project , will use all-sky cameras to search for faint auroral glow. It is a long shot, but Iceland lies beneath the auroral oval, a region surrounding the geomagnetic North Pole within which the aurora can regularly be seen. Even a non-detection could help constrain whether eclipse darkness can reveal aurora.

Total solar eclipses are brief, vulnerable to clouds and geographically specific, but they open a rare observing window onto the sun鈥檚 inner corona 鈥� and let scientists try bold ideas without first building a spacecraft.

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During the total solar eclipse on 12 August, scientists from around the world will have their eyes 鈥� and scientific instruments 鈥� on the sun. But even if you aren鈥檛 a scientist, you can help in their investigations, both during the eclipse and year-round.

A total solar eclipse occurs when the sun and moon line up just right so that the moon blocks out the entire disc of the sun from the perspective of Earth. It is a huge cosmic coincidence that both the sun and the moon happen to be just the right size and at the right distance to give us such a spectacle, and a scientifically useful one at that.

On 12 August, a total eclipse will be visible over parts of Europe and the Arctic and Atlantic oceans, with a partial eclipse covering much of Europe, Canada, north-west Africa and parts of the US. An eclipse like this one is visible from somewhere on Earth just once every 18 months approximately, so during each eclipse, scientists rush out to gather as much data as they can. Here are some ways that you can help out:

1. Record shadow bands from the path of totality: In the moments before and after a total solar eclipse, strange phenomena called shadow bands billow across the ground. These bands are caused by the combination of Earth鈥檚 atmosphere and the hidden disc of the sun 鈥� it is similar to the effect that causes more distant stars to twinkle. If you are in the path of totality, all you have to do to see them is set out a white sheet or piece of cardboard perpendicular to the direction of the sun. To , which aims to quantify how shadow bands differ based on altitude and distance from the centre of totality, just set up a camera to film the sheet.

2. Photograph the sun with your smartphone: The sun is very nearly spherical, but it isn鈥檛 perfect. One of the best ways to measure its shape with precision is to have lots of pictures taken from lots of different locations 鈥� that鈥檚 what does. It鈥檚 a smartphone app that you can set up and leave running as you enjoy watching the eclipse, and it will take carefully timed pictures to capture a phenomenon called Baily鈥檚 Beads, or the diamond ring effect. When the very last of the sun is about to be covered by the moon, the lunar landscape lets through tiny points of light, which shine along its edge. The same happens when the other side of the moon is just about to let the sun shine past it again, and these points of light are Baily鈥檚 Beads. When lots of photos of the beads, all precisely geolocated, are combined with a map of the lunar topography, that can give us an extraordinarily precise measurement of how far the disc of the sun is from a perfect circle.

3. Measure the darkening of the sky during the eclipse: Even if you are only going to see a partial eclipse, you can still help with scientific research. The Gaia4Sustainability project requires a little bit more equipment and set-up time, but once you have it sorted, you can leave it running all year round and keep collecting useful data. It consists of a small device with a bunch of sensors on it to measure the brightness of the sky and other meteorological factors, and the overarching goal of the programme is to measure light pollution so we can better understand its effects. But during the eclipse, the same sensors can be used to , and the more different spots the team has data from, the more they will be able to learn about atmospheric dynamics during eclipses.

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4. Hunt for sun-grazing comets: As is the case for pretty much all astronomical events, a huge portion of the world won鈥檛 be able to see August鈥檚 total eclipse at all. Not to worry! There are still ways to get involved in solar science. In the , you can download satellite pictures of the sun and look for moving objects on its outskirts. Some of the objects will be comets skimming past the sun, and once researchers know those comets are there, they can do more detailed research. A huge proportion of the known comets were discovered through Sungrazer. All it takes is a computer, an internet connection and some spare time.

5. Join a DEB observation team for next year: If you want to do something a bit more involved, the might be more up your street. It鈥檚 an scheme where teams receive training and some relatively basic equipment to observe eclipses across the path of totality, building up a huge repository of data that can then be used to study the evolution of the corona, the outermost layer of the sun鈥檚 atmosphere. Because of the training required, it is too late to join or create a DEB team for this year, but if you are going to be able to spot the 2027 eclipse that will sweep over northern Africa, you can sign up ahead of time.

Even during the eclipse, you shouldn鈥檛 look directly at the sun without a solar filter or eclipse glasses to protect your eyes.

On 12 August, a total solar eclipse will sweep across parts of Europe and the Atlantic ocean as the moon passes between Earth and the sun, blocking out sunlight. Parts of the US and Africa, along with the entire UK and much of Europe and Canada, will see a partial solar eclipse.

Where can I see the eclipse?

Totality, which occurs when the moon lines up perfectly with the disc of the sun and blocks it out entirely, will begin in Russia around midday before sweeping eastward across the Arctic ocean. It will pass just south of the North Pole and make landfall in northeastern Greenland just after 4.00pm local time.

The shadow will then rush along the eastern coast of Greenland at a speed of more than 3400 kilometres per hour. The maximum length of totality will be about 2 minutes and 18 seconds, as the moon鈥檚 shadow crosses from Greenland into the Atlantic ocean. It will cross to Iceland, at which point the eclipse will become visible from more heavily inhabited areas 鈥� everywhere it will have passed so far is home only to small villages, research stations and those specifically making the journey to see the eclipse. In Reykjav铆k, though, totality will be visible for just over one minute at 5.48pm local time. This is the first time a total eclipse has been visible in Iceland since 1954, and the last time one will be visible there until 2196.

After skimming the western coast of Iceland, the total eclipse will make another ocean crossing and reach land again in northern Spain just before 8.30pm local time, grazing the northeast corner of Portugal and crossing the Balearic Islands off Spain鈥檚 east coast before the sun sets and the eclipse is over.

What happens during a total solar eclipse?

During totality, when the disc of the sun is completely concealed by the moon, temperatures on the ground rapidly drop by several degrees and daytime transforms into twilight. The stars and the outer reaches of the sun become visible. Usually, the sun鈥檚 outermost layer, the corona, is completely lost in the glare from its far brighter inner regions, but when those are blocked out, its shimmering sheets of extraordinarily hot plasma become briefly visible to the naked eye. In all other phases of the eclipse, it is crucial to wear eclipse glasses or use a solar filter while looking directly at the sun to prevent eye damage, but during totality it is safe to look at the corona.

That is precisely what many solar scientists will be doing during August鈥檚 eclipse. Total eclipses mark a valuable opportunity to observe the corona and try to unravel its many mysteries, including why it is so much hotter than the sun鈥檚 surface.

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While the total eclipse will be short and only visible in a few areas, a partial eclipse, with the moon taking a 鈥渂ite鈥� out of the sun, will last much longer across about a quarter of the entire planet. In many locations across the northern US, all of Canada, much of Europe and northwestern Africa, the partial eclipse will last more than an hour. It won鈥檛 be as dramatic as a total eclipse 鈥� the corona will not become visible, and the ambient light levels and temperatures won鈥檛 drop as dramatically 鈥� but will be watchable for many more people. During a partial eclipse, eye protection is needed the whole time. If you don鈥檛 have eye protection, there are several ways to watch the eclipse without looking directly at the sun, including using a pinhole camera or even natural shadows to create a projection of the sun鈥檚 shape as the moon passes in front of it.

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If you are planning to enjoy the total solar eclipse on 12 August with your children, here are a few activities you can do with them before and during the eclipse, to help them understand what causes a solar eclipse and get the most out of the experience.

1. Build an eclipse viewer

On the days leading up to the eclipse, you and your children can get excited about the big event by building an eclipse viewer. There are a few ways to do this 鈥� the first of which is a simple pinhole camera using two pieces of paper. Cut a hole in one piece of paper and cover it with aluminium foil, then poke a small hole in the foil. On the day of the eclipse, hold the paper up to let the sun beam through the hole and it will project a version of the eclipse onto a second piece of paper you place on the ground.

A slightly more complicated version involves a cereal or shoe box, placing paper at one end and cutting two holes in the other end. Over one of the two holes, you place some tin foil and, again, pierce it so that the sunlight can get through. More details on how to make both versions here.

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2. Build a solar eclipse model

Another activity that can be done ahead of the eclipse is building, or acting out, a model of the sun, moon and Earth to understand what a solar eclipse is. To build it, all you need is three sticks and three balls to place on top of the sticks. You can paint them or colour them in so that they resemble the sun, moon and Earth. Make sure the sun is bigger than the moon. Then, you can show your kids what an eclipse is by placing the sun in the centre, and moving Earth around the sun and the moon around Earth. When the three line up, with the moon in between the sun and Earth, we get a solar eclipse. When the moon is on the other side of Earth from the sun, we get lunar eclipses.

Your kids can also act out a solar eclipse. Give one of them a torch or flashlight, making them act as the sun, and ask them to shine the torch on a wall. The other, who is the moon, can move around until they block the torch light. They can both play around with moving forwards and backwards, to show why the distances between the moon, Earth and sun matter when it comes to eclipses.

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3. Pop a balloon using sunlight

This is something that can be done on any sunny day. But on the day you are waiting for the total eclipse, you can show your kids how to use the power of sunlight to pop a balloon. You need a balloon and a magnifying glass for this activity. Blow up the balloon and then hold the magnifying glass up so that it magnifies the sunlight onto the balloon. Wait for a few minutes and, eventually, the balloon will pop. You can also make this more exciting by blowing up a white balloon inside a black one, and doing the same trick. The black balloon should pop, leaving the white balloon intact inside. You can use this to explain how black surfaces absorb sunlight, while light surfaces reflect them.

4. Play with shadows

On the day of the eclipse, while you are waiting for totality, the partial eclipse phase will last a few hours. You and your kids can get excited about the eclipse by noticing how shadows change, and playing around with this. If you have a tree nearby, look at the shadows it casts on the ground throughout the eclipse and you will see that they start to look like a sun with a bite taken out of it. This also works by crossing your fingers over each other and casting shadows on the ground. Another way to show the eclipse through shadows is using a colander, or anything with small holes in it. As the eclipse progresses, the shadows cast will start to take on the shape of the eclipse. You can punch a series of holes in a piece of paper to spell out a word or your kids鈥� names in these crescent shapes.

5. Draw shadows

This is another activity that can be done in the hours leading up to and after totality, again making the most of the interesting shadows created by a partially eclipsed sun. You can lay a big white piece of paper or sheet on the ground, and ask your kids to draw the shadows cast by different objects. If you do this at the start of the partial phase, and again closer to totality, they will be able to see how these shadows change as the eclipse progresses. You should notice that, in the lead-up to totality, shadows become much clearer as the amount of ambient light is reduced.

The following is an extract from our monthly Launchpad newsletter, in which resident space expert Leah Crane journeys through the solar system and beyond. You can sign up for Launchpad for free聽here.

It was 1919 when the moon did a perfectly natural thing 鈥� blocked our view of the sun 鈥� and changed our understanding of the universe forever. Astronomer Arthur Eddington was watching from the African island of Pr铆ncipe, observing the positions of stars and planets that became visible during the eerie daylight darkness. With most of the sun鈥檚 light dimmed, he was able to see how light from distant stars warped as it was deflected by our sun鈥檚 gravitational pull, an effect called gravitational lensing.

He confirmed his sightings with those of another expedition in Brazil, and these observations offered some of the first proof for Albert Einstein鈥檚 relatively new theory of general relativity. This description of how massive objects warp the fabric of space-time is now considered foundational, but at the time it was a revelation. It changed everything about how we think about gravity and the cosmos.

It also resulted in my of all time, published in The New York Times later that year: 鈥淟IGHTS ALL ASKEW IN THE HEAVENS; Men of science more or less agog over results of eclipse observations. EINSTEIN THEORY TRIUMPHS Stars not where they seemed or were calculated to be, but nobody need worry.鈥�

鈥淣obody need worry鈥� might seem a bit over the top, but watching a total solar eclipse can indeed make you feel inexplicably nervous. I saw my first one in 2017. It was absolutely unforgettable. You might think that an eclipse is just like an overcast day with a cloud drifting in front of the sun 鈥� after all, what鈥檚 happening is simply the moon passing in front of the sun and casting a shadow on Earth 鈥� but it鈥檚 astonishingly different.

The first thing you鈥檒l notice during a total eclipse is the shadow of the moon rushing over the ground towards you at speeds in excess of 2400 kilometres per hour. The area of shadow is quite wide 鈥� during the April 2024 eclipse it was up to 185 kilometres wide, but that changes slightly based on the exact orientations of the sun and moon. As the shadow grows near, the moon appears to take a bite out of the sun, and there鈥檚 a strange quality to the light, as if a fog has fallen.

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Then, suddenly, it goes dark. This is totality. Temperatures drop by up to 10 degrees. The only light comes from the sun鈥檚 outermost layer, called its corona, which ripples beyond the silhouette of the moon. It becomes so dark that some stars are visible in the sky. Many animals, including birds and insects, understandably seem to think that it鈥檚 nighttime, so the otherworldly twilight goes quiet except for the chirping of nocturnal insects that have awoken. I can鈥檛 say how you will feel, but for me it was a mix of awe and a strange, primal terror 鈥� the sun disappeared, and while my mind knew why, my body panicked at its loss.

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This seems to be a fairly common reaction, and not only in humans. Researchers studying animals during past total eclipses have found that while some simply went about their evening routines early, many of them showed signs of anxiety, running aimlessly or huddling together during totality.

Then, after just a few minutes, totality recedes just as quickly as it arrived. The shadow rushes away, the sun comes back out, and the birds and insects resume their chirping. The astronomers look up from their solar telescopes, groggy but excited at the treasure trove of data they鈥檝e gathered.

Over the thousands of years humans have been observing solar eclipses, we鈥檝e learned some pretty fascinating things. With the disc of the sun covered by the moon, its faint corona becomes visible, making an eclipse the perfect time to study the outer reaches of the sun. For example, scientists first discovered helium during a total solar eclipse. Eclipses are also the best times to observe the plumes of radiation and matter emanating from the surface of the sun through the corona. The corona itself is quite strange, and there鈥檚 plenty left to unravel about how it works 鈥� despite being far from the sun鈥檚 central fusion, the corona is millions of degrees hotter than the sun鈥檚 surface, and we still don鈥檛 know why.

Even if you鈥檙e not studying the sun鈥檚 mysterious layers, seeing a total solar eclipse is completely worth it. Those newspaper editors had it right more than a century ago: it鈥檒l leave you more or less agog.

A total solar eclipse occurs somewhere on Earth about every 18 months, and that has been the case for all of human history. Naturally, people have been studying these dramatic events for just as long, with the first known written record of an eclipse dating back more than 3000 years. In all that time, we have learned an astonishing amount from total eclipses about the sun, Earth and even the fundamental laws of physics.

For much of history, totality 鈥� the period of time in which the moon covers the entire disc of the sun 鈥� has been the only time that humans could see the sun鈥檚 faint outermost layer. This wispy shroud of plasma, called the corona, has been central to many of the scientific advances that have come from the study of eclipses.

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The corona is home to many of the sun鈥檚 most fascinating phenomena, including coronal mass ejections (CMEs), which occur when the sun鈥檚 churning magnetic field blasts strands and blobs of material out into space. CMEs that hit Earth can damage satellites and the electrical grid, and they can be extraordinarily dangerous to astronauts out in space, beyond the protection of Earth鈥檚 atmosphere.

鈥淭he magnetic activity of the sun changes over time and changes across the surface of the star,鈥� says at Johns Hopkins University in Maryland. So far, we don鈥檛 have a good way to predict this activity. But we might be able to begin doing so by studying the corona.

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A total solar eclipse isn鈥檛 the only way to look at the sun鈥檚 outermost layers 鈥� there is also an instrument called a coronagraph, which uses a shade to block out the disc of the sun in a sort of artificial eclipse. These instruments are important not only for studying our own star, but also for studying other, more distant stars and searching for any planets orbiting them that would otherwise be hidden in the glare of starlight. 鈥淭he inspiration to use coronagraphs to block out the light of other stars so we can look for their exoplanets comes from natural eclipses,鈥� says MacGregor.

The same dimness that makes the corona difficult to observe outside of totality also makes it an excellent target for spectroscopy. Spectroscopy works by breaking down light into its constituent wavelengths. This allows researchers to determine what elements are present in a material by the unique pattern of wavelengths each element emits or absorbs. Helium was discovered using spectroscopy during an eclipse in 1868, which was the first time any element was discovered by studying the skies.

Soon afterwards, astronomers found what appeared to be another new element in the corona, which they termed coronium, but it turned out to simply be iron heated up to extraordinary temperatures of millions of degrees. Even though it wasn鈥檛 a new element, this was a baffling find 鈥� the surface of the sun is only about 5600掳C, so how could the outermost layer be so sweltering?

Why the next solar eclipses are a unique chance to understand the sun

North America will see an annular solar eclipse on 14 October and a total eclipse in April 2024. 女生小视频s are preparing to use these spectacles to study our star's mysterious corona

鈥淚magine you鈥檙e at a campfire, and you start walking away from the campfire. And it should be getting colder, but it gets far hotter,鈥� says at the Center of Science and Industry in Ohio. 鈥淭hat鈥檚 what鈥檚 going on in the corona, and nobody knows why that is.鈥�

Solar eclipses even provided some of the first proof of Albert Einstein鈥檚 general theory of relativity, which governs how gravity behaves on large scales. One of the major predictions of general relativity is that massive objects should bend the trajectory of light as it passes by them. Einstein first presented his theory in 1915, and evidence for its veracity came in 1919, when astronomer Arthur Eddington observed starlight bending around the sun during a solar eclipse.

If you are planning to watch the solar eclipse on 12 August this year 鈥� whether you are in the path of totality or not 鈥� you will need some equipment to enjoy it fully.

The most important rule during an eclipse is not to look at the sun directly. The only time you can do so is during totality, the few minutes during which the sun鈥檚 light is entirely blocked by the moon. But part of the fun of an eclipse is the few hours on either side of totality in which you can watch the moon slowly creep across the sun.

You can use special solar filters, including eclipse glasses, to look at the sun directly. Or you can also see the eclipse using simple viewers made from just a few things that you probably have lying around. Here is how to make two kinds of eclipse viewer.

How to make a pinhole camera

For this viewer, all you need is some paper, aluminium foil, scissors and a pen. Cut a hole in the middle of one piece of paper, and cover it in foil. Stick the foil in place and punch a small hole in the middle of it using a pen, needle or other sharp object. On the day of the eclipse, all you have to do is hold this up to the sun and place a second piece of paper on the ground underneath. A little bright dot will appear on the second piece of paper 鈥� this is a projection of the sun. As the eclipse progresses, and the moon covers more of the sun, you will see the shape of the dot change.

How to make a box eclipse viewer

The second kind of eclipse viewer works in the same way, but the projection appears inside a box instead of on the ground. For this, you need paper, foil, scissors and a cardboard box 鈥� a cereal box or shoe box will work well.

Line one inner side of the box with white paper. Then, cut two holes in the opposite side, spacing them far apart. Tape a piece of foil over one hole and poke a small hole in it. The other hole will be where you look through.

On the day of the eclipse, hold the viewer up to your eye, with the sun behind you. A projection of the sun should appear inside the box, on the white paper you lined it with.

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Some people spend years planning a trip to see a total solar eclipse, yet the moment itself only lasts a few minutes at most. A well-taken photograph can help bring you right back to that moment years later.

Only those inside the path of totality will see a total solar eclipse. Most of the experience is identical, with partial phases necessitating solar eclipse glasses and solar filters, but midway through comes totality, when the moon completely blocks the sun for a few minutes. It is only during this time that eclipse glasses and solar filters can come off, and the sun鈥檚 corona can be seen with the naked eye and photographed. This is the shot everyone wants.

The good news is that with a bit of practice even a novice can capture a great image. Here鈥檚 how to photograph the eclipse, no previous experience or fancy camera equipment necessary.

How to photograph a total solar eclipse using your smartphone

If you are in the path of totality, forget about handheld video and zooming in on the eclipsed sun 鈥� the results using a smartphone will be disappointingly dark. Instead, concentrate on taking a wide-angle shot that will showcase the beauty of totality using silhouettes of people and objects.

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Just before it gets dark, put your phone into wide-angle mode. Focus on something in the middle distance and lock the focus by pressing and holding the screen with your finger. Use burst mode to capture images in quick succession as totality begins. That way you will be able to capture the 鈥渄iamond ring鈥�: the last and first beads of sunlight peeking around the moon just before and after totality.

How to photograph a total solar eclipse using a camera

If you have a manual DSLR or mirrorless camera and a variety of lenses, you can choose whether to capture a wide-angle shot or take a close-up of the eclipse. During the partial phases, you will need to use a solar filter.

Just before totality, check your focus on the partially eclipsed sun and then set your camera to bracket mode (when you take the same image at three different exposures). 鈥淢ake sure your camera is shooting low ISO before and after totality, between 200-400, to reduce any noise,鈥� says , a nature photographer. Remove the solar filter during the diamond ring, take bracketed shots during totality and don鈥檛 forget to put the solar filter back on as soon as you see the second diamond ring at the end of totality.

How to photograph a partial solar eclipse

To take an impressive shot of a partially eclipsed sun with your smartphone you need to use a solar filter and keep the phone still. The latter can be done by using a tripod and then engaging a shutter delay for a few seconds. For a filter, using a pair of eclipse glasses is fine. If you have a spare pair, try cutting out one lens and taping it across your phone鈥檚 camera lens. Another option is to buy a smartphone eclipse filter from a company like or .

Although smartphones don鈥檛 tend to get damaged by being pointed at the sun, never point a manual camera at the partially eclipsed sun unless its lens is protected by a solar filter. You can buy expensive glass solar filters or make your own using inexpensive Baader AstroSolar Safety Film.

Though the steps needed to photograph a partial eclipse are a little more complicated than taking a standard selfie, you can practice beforehand whenever you have a clear view of the sun. 鈥淢anually focus and set the exposure,鈥� says , a photographer based in New York, who teaches eclipse photography workshops. He recommends using an aperture of f/8-11, a shutter speed of 1/800 and ISO 100.

And make sure you don鈥檛 spend the whole time fiddling with your camera. 鈥淎s much as you want to shoot the event, take some time to put the camera down and take it in because it鈥檚 one of the most incredible things you鈥檒l ever see,鈥� says Mezeul.

In 331 BC, the Macedonian warlord Alexander the Great marched his army into the territory of the Achaemenid Empire and its king Darius III. Alexander went into the battle highly confident, partly because he believed there had been a good omen: a a few days before, on . The Battle of Gaugamela, in what is now Iraqi Kurdistan, ended in a decisive victory for Alexander. Darius fled for his life, and Alexander soon took over the entire Achaemenid Empire. That鈥檚 one powerful lunar eclipse.

From our perspective, it is easy to look at such stories and dismiss ancient peoples鈥� ideas about phenomena like eclipses as ignorant and superstitious. But careful examination of ancient texts and oral traditions reveals that people understood something of the mechanics of the solar system and even had some ability to predict eclipses.

Mesopotamian astronomy

The oldest known written records of astronomical phenomena, including eclipses, come from Mesopotamia, according to at the University of Canterbury in New Zealand in her 2011 book .

Montelle describes a set of several dozen cuneiform tablets known as the En奴ma Anu Enlil, 13 of which contain information about lunar and solar eclipses, compiled between 2000 and 1600 BC. The main purpose of the tablets seems to have been to alert the king about omens. In the process, the astronomers began to see patterns. For example, they recognised that lunar eclipses only occur during a full moon and solar eclipses during a new moon. Later, Assyrian astronomers may have noticed that lunar eclipses tend to recur either every six months or after a longer interval.

These early astronomers faced two major challenges in predicting eclipses. The first was that eclipses do recur in predictable ways, but only over very long timescales. Near-identical eclipses occur every 6585.3 days, or just over 18 years: . To spot this 18-year saros cycle, you need decades of observations, and a good calendar to boot.

Secondly, eclipses are never visible from the whole of Earth鈥檚 surface. The eclipse that comes 18 years after the last one might only be visible from the other side of Earth. Confined to one corner of the planet, the Mesopotamians only knew about the eclipses that were seen from their area 鈥� giving them an incomplete picture.

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These difficulties were less pronounced for lunar eclipses, which can be seen from Earth鈥檚 entire night side and often last over an hour. In contrast, solar eclipses are only visible along a narrow band of Earth鈥檚 surface and last mere minutes. Lunar eclipses are inherently more predictable, which is why Mesopotamian astronomers were already spotting patterns in them.

Mayan eclipse records

Similar stories played out on the other side of the planet, for instance in the Maya society of Mesoamerica. The Maya had an elaborate religion that included ideas about cosmology.

One of the most illuminating Mayan artefacts is a painted book called the Dresden Codex, named for the city in Germany where it is housed. It was probably created around AD 1210, perhaps in the Mayan city of Chich始en Itza始. In her 1999 book , at the University of Florida described a series of eclipse tables in the Dresden Codex. The tables seem to describe time intervals in which eclipses could occur, serving as predictions.

Recognising that the sun was essential for their survival, Mayan astronomers viewed eclipses as threatening. In some traditions, the end of the world would begin with an eclipse.

Nevertheless, there were limits. 鈥淭he Dresden predictions are only accurate to the day, and they only indicate that the Maya calculated that somewhere on Earth there would be an eclipse on that date,鈥� says Milbrath. Like the Mesopotamians, the Maya were unable to predict where on Earth eclipses would be visible.

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In subsequent centuries, astronomer-priests became good enough at predicting eclipses that they may have got sneaky about it.

In the early 1500s in the city-state of Tenochtitlan, in what is now Mexico, Mexica people (sometimes called Aztecs) carved a large circular stone. Now known as the Aztec calendar stone or sun stone, its densely packed symbols encode information about cyclical creation and destruction, including imagery of the sun and moon.

In , Milbrath argued that some of the imagery relates to a solar eclipse. She suggested the central image is the death of the sun god Tonatiuh during an eclipse, which was associated with the end of the world. In her view, the stone predicts on a particular day of the year.

However, there was never an eclipse on this day during Aztec rule and there won鈥檛 be until 2078. Milbrath says this revelation, shown through , suggests astronomer-priests were trying to ensure their own long-term position by predicting a cataclysm they knew wouldn鈥檛 happen, but which they could use to scare the populace.

We know all of this because these cultures had writing. But what about societies that didn鈥檛?

Eclipses in oral cultures

Understanding and predicting eclipses looks much harder if your society doesn鈥檛 have writing. Keeping track of when and where eclipses have happened would be tricky enough; spotting patterns and using them to predict future eclipses sounds like a tall order. Nevertheless, there is evidence that some non-literate societies pulled it off 鈥� at least for lunar eclipses.

at the University of Melbourne in Australia has spent years studying the astronomical knowledge of Aboriginal Australians. He summed up his findings in his 2022 book , co-authored with Aboriginal and Torres Strait Islander Elders.

When Hamacher started, the popular belief was that Aboriginal Australians had 鈥渟ome stories and names for stuff鈥�, but no 鈥渞eal astronomy鈥�. 鈥淚t didn鈥檛 take 10 seconds of looking into it to realise that鈥檚 total rubbish,鈥� he says.

In a 2011 study, Hamacher and his colleague described several dozen . Like the Maya, they often viewed eclipses as threatening. But they also understood something of the mechanics.

For instance, the Pintupi people of the Central desert said a solar eclipse was caused by Pira (the moon man) covering the sun, either with his hand or body. 鈥淭here were so many Aboriginal traditions that described this event as being when the moon covered up the sun,鈥� says Hamacher. This is striking because the moon isn鈥檛 visible before a solar eclipse. 鈥淧eople know where celestial objects are even when you can鈥檛 see them.鈥�

In a chapter of his book, written with Uncle Ghillar Michael Anderson of the Euahlayi Nation, Hamacher describes the Zugubau Mabaig (鈥渁stronomers鈥�) of the western Torres Strait Islands. A key duty of a Zugubau Mabaig was to perform a ceremony called Melpal Mari Pathanu (鈥渢he ghost has taken the spirit of the moon鈥�) during an eclipse. The Zugubau Mabaig recited the names of the Torres Strait Islands until the moon emerged.

Crucially, the ceremony was planned in advance, according to a man named David Bosun whose father was a Zugubau Mabaig. 鈥淲hich means people had to predict when that lunar eclipse [was] going to occur,鈥� says Hamacher.

We don鈥檛 know how the Zugubau Mabaig predicted the lunar eclipses: a lot of Aboriginal Australian astronomical knowledge was lost during European colonisation. However, Hamacher says one element that may have helped is how durable oral traditions can be.

In a study published in November 2023, he and his colleagues studied . The traditions include a description of the flooding of the land bridge that once connected Tasmania to mainland Australia, about 12,000 years ago. They also refer to the star Canopus as being located near the southern celestial pole, which was the case about 14,000 years ago.

鈥淣ow that we鈥檙e understanding how oral tradition works a bit better, we know that huge bodies of knowledge can be committed to memory and they can last for thousands of years,鈥� says Hamacher. This may help explain how societies without writing could nevertheless predict phenomena as intermittent as eclipses.

Predicting eclipses may seem like an esoteric skill for hunter-gatherer societies, but Hamacher says we shouldn鈥檛 be surprised. 鈥淭he sky is how you measure time,鈥� he says. 鈥淚 mean really, how do you measure time without the sun, moon or stars?鈥� Studying it offered ways to keep track of crucial cycles like tides and animal migrations. 鈥淎stronomy is always something that ancient cultures would have figured out how it works, because it would be necessary to thrive and survive.鈥�